<html>
<head>
<meta charset='utf-8'>
<script src="https://code.jquery.com/jquery-1.10.1.min.js"></script>
<style>
    #langs p {display:none;}
    #langs p.first {display:block;}
</style>
</head>
<body>
<button id="slideUp">Скрыть</button>
<button id="slideDown">Раскрыть</button>
<script type="text/javascript">
$(function() {
    $('#slideUp').click(function(){
         $(this).slideUp();
    });
    $('#slideDown').click(function(){
         $('#slideUp').slideDown();
    });
});
</script>
</body>
</html>